CUBA, Mo.—Democratic Sen. Claire McCaskill is spending the August recess trekking through Republican strongholds in rural Missouri as she gears up for what's expected to be a fierce battle for a third term.

Missouri has shifted even further to the right since the former state auditor joined the Senate in 2007. Republicans haven't lost a statewide race since 2012 when McCaskill won her second term, and they haven't lost a presidential race for more than two decades.

Although McCaskill likely still enjoys strong support in the predominantly Democratic metropolitan areas of St. Louis and Kansas City, where she once served as a county prosecutor, the changing demographics signal that might not be enough. During the monthlong congressional recess, she's holding town halls in dozens of small towns and cities — including some areas where she hasn't fared well in past elections.

Appearing Thursday at the Missouri State Fair in Sedalia, McCaskill said she has an "independent streak." At an earlier town hall in Cuba, a city of fewer than 3,500 people that's roughly 80 miles (130 kilometers) southwest of St. Louis, she pitched herself as a "believer in compromise."

"'Right in the middle' is an accurate way to describe me," McCaskill told the roughly 30 people who showed up.

McCaskill is one of 10 Senate Democrats up for re-election next year in states won by President Donald Trump, in many cases by wide margins. The challenge for Democrats could be tougher because turnout in big cities could be lower without a presidential race topping the ballot.

Rural turnout could also be critical for Michigan's Debbie Stabenow and Wisconsin's Tammy Baldwin, two other Democratic senators facing tough re-election challenges.

McCaskill faces tough competition if she matches up with Attorney General Josh Hawley, a Republican who won more votes in Missouri last year than Trump did and is exploring a potential bid against her.

Retired Saint Louis University political scientist Steven Puro said next year, it's vital for McCaskill to carry votes far beyond Kansas City and St. Louis.

"The rural strategy has to work for her," Puro said. "Because if it doesn't, she's out of luck."

In her successful 2006 and 2012 campaigns, McCaskill made a series of small-town stops in an attempt to court rural voters. Her itinerary in rural areas this year is aggressive, with dozens of town halls already under her belt and more to come in the next few weeks.

While she lost in many counties in 2012, she had some victories and trailed closely behind her Republican rival, former Rep. Todd Akin, in some traditionally GOP areas. However, Akin tumbled in the polls after commenting on a talk show that women's bodies have ways of avoiding pregnancy from what he called "legitimate rape."

"It's not always about winning an area, but just siphoning off as much of the vote as you can for your cause," said Randy Hagerty, a political scientist at Truman State University in northern Missouri.

Republicans are openly mocking McCaskill's outreach in rural areas. State Republican Party spokeswoman Keelie Broom in a message posted on the party's website predicted McCaskill will "conveniently play up her down-home 'daughter-of-rural-Missouri' act now she is up for re-election," adding that Republicans "aren't fooled by this." McCaskill is a Rolla native who was later raised in Houston and Lebanon, Missouri, before moving to Columbia as a child.

"Rural Missouri voters haven't seen hide nor hair of Sen. McCaskill in six years," Missouri Republican Party Executive Director Austin Stukins said. "Now that it's time for re-election, she suddenly pretends to care."

McCaskill said she's held town halls throughout her time in the Senate, and pointed to ones held in 2009 during the contentious debate over former President Barack Obama's health care law. On Thursday, she said town halls this year are "not an election year thing."

"In this world, you're kind of darned if you do and darned if you don't," she said earlier in Cuba. "If I wasn't coming, they'd say I was hiding."

McCaskill has long painted herself as a moderate, and during the Cuba town hall touted support for the Keystone XL pipeline and opposition to Sen. Harry Reid's bid for minority leader when Democrats lost control of the Senate in 2014, for example.

Her recent work has focused on issues including human trafficking, opioid abuse and veterans' issues — topics without partisan baggage that could resonate across party lines.

Republicans are trying to counter that narrative, arguing instead that she's an obstructionist to Trump's agenda and attempting to tie her to Senate Minority Leader Chuck Schumer and fellow Democratic Sen. Elizabeth Warren.

In a rodeo-themed ad against her that ran in southeastern Missouri markets during a Sikeston rodeo this month, the National Republican Senatorial Committee claimed McCaskill "would rather cozy up to radical liberals in Washington than make America great again."

That message seemed to echo criticism from at least one person at McCaskill's Cuba town hall.

"I'm totally, 100 percent behind our president and she is not. She is there obstructing," said Vivian Simpson, 56, a Democrat-turned-Republican. She also expressed skepticism of McCaskill's rhetoric in light of the upcoming election.